Dh has declined a research job offer, very politely and thanked them for the opportunity, apologised for inconvenience caused etc all the standard stuff but the boss has written back asking why! I don't really think he has to tell her but he wants to keep communication going (thinking collaboration later maybe). How can he politely put it? The reasons are that he doesn't like the idea of having to go on regular visits to another city 2 hours away to collect data and check on students. He doesn't like the fact that she's looking for another position herself (atleast he found that out through an ex-colleague and she confirmed it) and promises to take him with her if she gets one so can only give an initial 2 year contract now and the salary doesn't match his present pay! I don't think he should put too much detail but he doesn't want to NOT answer her. He applied thinking it might be a promotion on his present job but it isn't.
He just needs to reply saying that he found the job wasn't going to be what he had thought and so he's declined it. Might be a lesson to her that she can't recruit good staff if she isn't up front about the role and her aspirations for it.
I think maybe it's best if he states that it's a bad time to move the family and something about long term stability and leave the other reasons? He doesn't want to sound too fussy if he wants to maybe stay in touch for the future.
My only reason for asking would be because I really wanted the candidate and want to know if his reasons might be a negotiating point, particularly over salary .... or working from home option if he doesn't like the travelling.
If he really doesn't want the job, then responding with something she will be unable to negotiate on (length of contract?) is the answer. If he wants the job on different terms, cite the points he wants to negotiate.